Cast-in-place box culverts are used with pipe for handling drainage water and sewage. Box culverts provide a large area of flow in a relatively small space. Many construction projects, such as supermarkets and malls, require 1,500 to 3,000 feet of box culverts. It is conventional construction to dig the necessary trenches and cast the box culverts in place. This is a time consuming and costly project. Cast-in-place box culverts require forms that are reinforced and placed in the trenches. Concrete mix is transported by trucks to the job site and placed in the forms to make the box culvert. After the concrete has set the forms are removed. Fabrication of a cast-in-place box culvert is subject to adverse weather conditions and in many cases difficult accessibility to the job site.
Wet pre-cast concrete box culverts were developed for fabrication in the plant and then hauled to the job site. The wet cast system of making a culvert has a disadvantage in that considerable time is necessary before the jackets and cores can be removed from the wet concrete culvert. This requires a substantial investment in box forms and produces a relatively low production rate, thereby making a long run contract expensive.